Fujisawa EP 184162 discloses a group of compounds represented by formula A ##STR3## wherein R.sup.1 is hydroxy or protected hydroxy,
and salts thereof.
As is evident from the above formula, there are many asymmetry centers and therefore, a large number of possible stereoisomers exist for any given meaning of the substituents.
On the other hand, although on page 4 in EP 184 162 it is mentioned that there may be one or more coniormer(s) or stereoisomeric pairs such as optical and geometrical isomers due to asymmetric carbon atom(s) and double bond(s), for none of the compounds specifically disclosed in EP 184 162 is there any indication of the exact stereochemical configuration.
This is so in particular for the compound named FK 900506 (FK 506), which is the object of Examples 1 to 3 therein, its derivative hydrogenated at the allyl group to an n-propyl group, which is the object of Example 21 therein, and its derivative dehydrated between positions 14 and 15, which is disclosed in Example 17 therein. From the formula and the names indicated on page 32, 95 and 98 of EP 184 162 it is not apparent what confiuration FK 506 and these two derivatives have.
The configuration of FK 506 has however been published in the scientific literature, e.g. in H. Tanaka et al., J. Am. Chem. Soc. 109 (1987) 5031-5033, T. Kino et al., J. Antibiotics 40 (1987) 1249-1255 and T. Taga et al., Acta Cryst. C43 (1987) 751-753.
It appears therefrom that FK 506 and, by implication, the two derivatives thereof mentioned above, have the configuration indicated above for formula I of the present invention, except that at the carbon atom numbered I7 the configuration is reversed, i.e. it is the R configuration, whereas in formula I above the S configuration is shown.